Patent GB-1103987-A (GB)
Title: The preparation of des-a-steroids
IPC: C07C309/65
Filed: 1965-03-29
Abstract: The invention comprises compounds having the formula <FORM:1103987/C2/1> wherein R10 represents a hydroxy or esterified hydroxy group, R2 represents a hydrogen atom or a lower alkyl group or R10 together with R2 represents a 17b -hydroxy-17a -(lower alkanoic acid) lactone group, R31 represents a hydrogen atom or a lower alkyl, hydroxy or esterified hydroxy group, X represents a hydrogen or halogen atom or a lower alkyl, lower alkylthio or lower-alkanoylthio group in the 6- or 7-position, compounds of the formula <FORM:1103987/C2/2> wherein X is as defined above, R32 represents a hydrogen or fluorine atom or a lower alkyl, hydroxy or esterified hydroxy group, R5 represents a hydrogen or halogen atom and R60 represents a hydrogen or halogen atom or lower alkyl, hydroxy or esterified hydroxy group, 20-ketals thereof, 16a ,17a -ketals and acetals of those compounds in which R32 and R60 each represent a hydroxyl group, derivatives thereof in which the 20-oxo group is reduced to a 20-hydroxy group and the corresponding derivatives in which said 20-hydroxy group is esterified, compounds of the formula <FORM:1103987/C2/3> wherein X, R32, and R60 have the above significance, OA represents a hydroxy or esterified hydroxy group, 17a ,20:20,21 - bis(methylenedioxy) derivatives of those compounds in which OA and R60 each represent a hydroxy group, 16a ,17a -ketals and acetals of those compounds in which R32 and R60 each represent a hydroxy group, 17a ,21-ketals and acetals of those compounds in which OA and R60 each represent a hydroxy group, derivatives thereof in which the 20-keto group is reduced to a 20-hydroxy group and the corresponding derivatives in which said 20-hydroxy group is esterified, compounds having the formula <FORM:1103987/C2/4> wherein R10, R2, and R31 are as defined above or R10 together with R2 represents an oxo, lower alkylenedioxy or 17b -hydroxy-17a -(lower alkanoic acid) lactone group, X0 represents a hydrogen atom or a lower-alkyl, lower-alkylthio or lower-alkanoylthio group in the 6- or 7-position or a halogen atom in the 7-position and EO represents an esterified hydroxyl group, compounds having the formula <FORM:1103987/C2/5> wherein R5, R60, R32, X0 and EO are as defined above, 20-ketals thereof, 16a ,17a -ketals and acetals of those compounds in which R32 and R60 each represent a hydroxy group, derivatives thereof in which the 20-oxo group is reduced to a 20-hydroxy group and the corresponding derivatives in which said 20-hydroxy group is esterified, compounds having the formula <FORM:1103987/C2/6> wherein R32, R60, OA, X0 and EO are as defined above, 17a ,20:20,21 - bis(methylenedioxy) derivatives of those compounds in which OA and R60 each represent a hydroxy group, 16a ,17a -ketals and acetals of those compounds in which R32 and R60 represent a hydroxy group, derivatives thereof in which the 20-keto group is reduced to a 20-hydroxy group and the corresponding derivatives in which said 20-hydroxy group is esterified, and a process for the preparation of des-A-androst (or pregn)-9-en-5-ones, which comprises either subjecting a 3-oxoandrost (or pregn)-4-ene to ozonolysis, pyrolyzing the alkali-metal salt of the resulting 5-oxo-3,5 - seco - A - norandrostan (or norpregnan) - 3-oic acid and introducing a 9,10-double bond into the resulting des-A-androstan (or pregnan)-5-one by means of a 2-step sequence of halogenation and dehydrohalogenation or esterifying an 11-hydroxy-androst(or pregn)-4-en-3-one so as to form an esterified hydroxy group in the 11-position, oxidizing the resulting ester by ozonolysis or by treatment with hydrogen peroxide to form an 11-(esterified hydroxyl)-5-oxo-3,5-seco-A-norandrostan (or norpregnan)-3-oic acid, converting said acid into an alkali metal salt and pyrolysing said alkali-metal salt or oxidizing an 11-hydroxy-androst (or pregn)-4-en-3-one by ozonolysis or by treatment with hydrogen peroxide, converting the resulting 5 - oxo - 11 - 5 - oxo - 11 - hydroxy - 3,5 - seco - A -norandrostan (or norpregnan) - 3 - oic acid 3,11-lactone into an alkali-metal salt of the corresponding keto-acid, pyrolyzing said alkali metal salt, esterifying the resulting 11-hydroxy-des-A-androstan (or pregnan)-5-one so as to form an esterified hydroxy group in the 11-position and treating the resulting 11-(esterified hydroxy) des-A-androstan (or pregnan)-5-one with a basic agent to remove the acid corresponding to the esterified hydroxy group with concomitant formation of a 9,10-double bond.